Magnetic resonance imaging of knee trauma.

This article reviews the magnetic resonance (MR) appearance of normal knee anatomy and the role of MRI in the evaluation of knee trauma. Images acquired in the sagittal plane are the most useful. A combination of T1- and T2-weighted spin echo pulse sequences is most commonly employed. A meniscal tear is identified by an intrameniscal signal which extends to the joint surface. MR and arthroscopic findings agree in more than 90% of patients. It is important to be familiar with the MRI appearance of normal anatomic variants that may be confused with meniscal tears: the transverse geniculate ligament, the hiatus of the popliteal tendon sheath, and the meniscofemoral ligaments. Tears in the anterior cruciate, posterior cruciate, and collateral ligaments are also depicted.